An arrangement in which information about position, direction of travel, and speed of travel of a subject vehicle and another vehicle is exchanged by means of inter-vehicle communication therebetween, and when there is a possibility of the subject vehicle and the other vehicle simultaneously entering an intersection present in the direction of travel of the subject vehicle on map data, a warning is issued to the driver of the subject vehicle by means of a buzzer, etc. is known from Patent Document 1 below.
An arrangement in which, in order to prevent an intersection collision when a vehicle traveling on a non-priority road enters an intersection with a priority road, a coverage area is set on the non-priority road prior to the intersection, when the vehicle on the non-priority road enters the coverage area, data on the vehicle on the priority road is transmitted to the vehicle on the non-priority road by road-vehicle communication, and when there is a possibility of a collision a warning is issued to the driver or automatic braking is carried out is known from Patent Document 2 below.